1. Field of the Invention
This invention relates to apparatus for cleaning small, ferrometallic, precision items, e.g., dental burs, watch components or small, delicate, precision machine parts. Items of this type acquire debris lodged in grooves and other inaccessible areas and conventional cleaning devices have not provided an adequate means for cleaning such items.
2. Description of the Prior Art
Heretofore, especially in the case of dental burs, the burs had to be cleaned manually with a steel brush which did not get the grooves adequately clean. When debris is allowed to dry in the grooves of the bur, certain dental materials are practically impossible to remove. Other items which need to be cleaned, e.g., watch components and precision machine parts, present similar problems. Many such parts are characteristically non-spherical, of a ferromagnetic material, and are not initially permanently magnetized or designed as permanent magnets as compared to permanent magnets designed as such and formed of ferromagnetic material with a relatively high coercive force. Dentists, watchmakers, machinists and others have been in need of an efficient, economical and expedient means by which various small, metallic articles of the type mentioned can be properly cleaned. As far as is known, a cleaning device which adequately satisfies this need has not previously been available. Although not useful for the purposes of this invention, mixing devices are known which incorporate magnets to achieve the desired stirring effects. For example, U.S. Pat. No. 2,999,673 discloses a magnetic mixing device which utilizes a magnet rotated by a drive motor and a bar of magnetic material placed within a closed fluid path which is caused to rotate by the rotating magnet to establish a mixing condition within the fluid path. U.S. Pat. Nos. 3,995,835 and 3,752,443 provide further examples of magnetic mixers. Also, U.S. Pat. No. 2,573,319 illustrates an inductive stirring device which utilizes magnetic systems in obtaining the desired stirring effect.
While these forms of stirring and mixing utilize magnets, they are not practical for use in cleaning precision items, such as have been noted above. That is, they are impractical largely because there are no means provided for maintaining a separation between any discrete objects which may be placed in the mixing vessel. The real need has been for a device in which a number of items can be cleaned at the same time but which will prevent these items from coming into contact with each other or any other object in the container during the course of the cleaning operation.